1. Technical Field
The following description relates to an image processing method, an image processor, and a stereoscopic image display device using the image processor, which obtain high readability on a text area when implementing stereoscopic images (hereinafter, referred as “three-dimensional (3D) images”) by a patterned retarder method.
2. Discussion of the Related Art
Techniques for implementing a stereoscopic image display device to display three-dimensional (3D) images are classified as either a stereoscopic technique or an autostereoscopic technique. Generally, a stereoscopic technique creates or enhances the illusion of depth in an image by presenting two offset images separately to the left eye and the right eye of the user viewing the 3D image and requires the use of glasses to view the 3D image. The stereoscopic technique uses a binocular parallax image between the left and right eyes of a viewer and includes a glasses method and a non-glasses method. The glasses method is classified into a patterned retarder method (hereinafter, referred to as a “PR type”) and a shutter glasses method. In the PR type, a three-dimensional (3D) image is implemented by using polarization glasses after displaying the binocular parallax image on a direct view-based display device or a projector by changing polarization direction. In the shutter glasses method, a 3D image is implemented by using liquid crystal shutter glasses after displaying the binocular parallax image on a direct view-based display device or a projector in a time division manner. In the non-glasses method, a 3D image is implemented by using an optical plate such as a parallax barrier or a lenticular lens for separating an optical axis of the binocular parallax image.
FIG. 1 illustrates an exploded perspective view of a conventional PR type stereoscopic image display device. With reference to FIG. 1, the PR type stereoscopic image display device implements the 3D image using a polarization characteristic of a patterned retarder PR disposed on a display panel DIS and polarization characteristic of polarized glasses PG which a user wears. The PR type stereoscopic image display device displays a left-eye image on odd-numbered lines of the display panel DIS and displays a right-eye image on even-numbered lines of the display panel DIS. The left-eye image is converted into left-circularly polarized light by the patterned retarder PR. The right-eye image is converted into right-circularly polarized light by the patterned retarder PR. A left eye polarizing filter of the polarized glasses PG passes through only the left-circularly polarized light, and a right eye polarizing filter of the polarized glasses PG passes through only the right-circularly polarized light. Therefore, the user views only the left-eye image through his or her left eye and views only the right-eye image through his or her right eye.
In case of the PR type stereoscopic image display device, a boundary portion of the 3D image such as between an object and another object or between an object and a background may be unevenly shown, for example, in steps. Such a phenomenon is known as “jagging,” “jagness,” or a “zigzag artifact.” In the following description, a shape in a 3D image that looks like a step pattern is referred to as “jagging.”
Meanwhile, the 3D image may include a text area which displays texts. The text area of the 3D image may have poor readability due to jagging.